As Tesla Motors pumps up production and lays off staff, it seems that one disgruntled employee at Elon Musk's electric car company Tesla has decided to throw a wrench in the works by leaking a large amount of sensitive data to third parties.

According to an email Musk just sent to Tesla staff, the employee admitted to the leak and said it was revenge for not receiving a promotion.

The identity of the employee is currently unknown.

"The full extent of his actions are not yet clear, but what he has admitted to so far is pretty bad," Musk said in the email.

"His stated motivation is that he wanted a promotion that he did not receive. In light of these actions, not promoting him was definitely the right move."

It's unclear who the leaked Tesla data was sent to, but it comes at a pivotal time for the company, which is trying to make electric cars affordable, practical, and more mainstream.

While Musk didn't go into specific detail about the extent of the espionage, from the sounds of it, this wasn't just a one-off harmless moment of someone blowing off steam; evidence from his email to employees points to a deliberate, pernicious campaign to bring the company down from the inside.

Musk says the unnamed employee told him that he had made "direct code changes to the Tesla Manufacturing Operating System under false usernames," Musk wrote in the email, CNBC reported.

The Tesla CEO doesn't think this was some random isolated act of vengeance, either.

Musk also mentions that "there are [sic] a long list of organizations that want Tesla to die," including competing car manufacturers and oil companies.

"This is when outside forces have the strongest motivation to stop us," said Musk in his email.

The leak comes after another "strange incident" in which a fire broke out in a Tesla plant in California.

It's unclear whether the fire was set intentionally, but it was quickly extinguished.

Musk urged his staff to be vigilant for more potential sabotage:

"Most of the time, when there is theft of goods, leaking of confidential information, dereliction of duty or outright sabotage, the reason really is something simple like wanting to get back at someone within the company or at the company as a whole. Occasionally, it is much more serious."